The advanced television systems committee (ATSC) standard used for terrestrial digital television (DTV) is based on single-carrier VSB modulation. ATSC mobile/handheld (ATSC M/H) standard is a mobile/handheld variant of the ATSC standard. The digital multimedia broadcast-terrestrial/handheld (DMB-T/H) standard is another DTV standard that uses single-carrier modulation technique. Time-domain algorithms used in conventional DTV receivers may be very computation intensive because of their complex equalizers implementations. Accordingly, the time-domain demodulation algorithms may not be feasible implementation based on (or using) programmable processors. However, frequency-domain demodulation is considered as a viable way of implementing receivers, e.g., using programmable processors, for one or more of the above DTV standards.
Conventionally, the signals received at DTV receivers (ATSC, DMB, or any other receiver) suffer from multi-path or echo interference. Accordingly, to mitigate such interference, the DTV receivers may be configured to perform channel equalization. However, multi-path profiles of the signals handled by the DTV receivers (particularly, the mobile receivers) may be time-varying, and as such, the receivers may need to be designed and configured to handle dynamic channel equalization.
Frequency-domain implementation of the DTV receivers (and equalizers therein) work on blocks of samples or data. The block sizes may be selected relatively large to achieve the computational gains (e.g., in computing Fourier transforms, and other operations) needed for real-time implementation in software. However, as a result of such large block sizes, the equalizers may not be able to adapt the channel frequency response fast enough to be able to efficiently equalize time-varying channels and accurately recover the transmitted signal. Additionally, conventional equalizer or DTV receiver implementations may only consider one previous channel frequency response estimate to obtain a new channel frequency response (for a new data block). As such, those implementations fail to consider an extended history of channel frequency responses, and do not exploit the statistical properties of the time-varying channel to obtain an accurate estimate of a new channel frequency response.